EGR system having EGR valve with purge air chamber

Abstract

An exhaust gas recirculation system for an internal combustion engine includes an intake manifold, an exhaust manifold, and a turbocharger compressor coupled with the intake manifold. The exhaust gas recirculation system includes an EGR valve fluidly coupled between the exhaust manifold and the intake manifold. The EGR valve includes a valve stem and a purge air inlet associated with the valve stem. The purge air inlet is in fluid communication with the compressor.

1. An internal combustion engine, comprising:
 a block defining at least one combustion cylinder; 
 an intake manifold fluidly coupled with at least one said combustion cylinder; 
 an exhaust manifold fluidly coupled with at least one said combustion cylinder; 
 a turbocharger including a turbine fluidly coupled with said exhaust manifold, and a compressor fluidly coupled with said intake manifold; 
 an EGR valve fluidly coupled between said exhaust manifold and said intake manifold, said EGR valve including a valve stem, a shield surrounding said valve stem, a purge air inlet associated with said valve stem, said purge air inlet being in fluid communication with said compressor, and a purge air chamber defined by said shield, said purge air chamber in communication with said purge air inlet. 
 
   
   
     2. The internal combustion engine of  claim 1 , wherein said EGR valve includes a purge air port terminating at said purge air inlet. 
   
   
     3. The internal combustion engine of  claim 1 , wherein said EGR valve is fluidly interconnected between an EGR cooler and said intake manifold. 
   
   
     4. The internal combustion engine of  claim 1 , including an aftercooler interconnected between said compressor and said intake manifold, said purge air inlet being in fluid communication with said compressor upstream from said aftercooler. 
   
   
     5. The internal combustion engine of  claim 1 , wherein said EGR valve includes an open frame defining each of said purge air inlet and said purge air chamber. 
   
   
     6. The internal combustion engine of  claim 5 , wherein said valve stem has a longitudinal axis, and said purge air inlet and said purge air chamber define a cross flow direction transverse to said longitudinal axis. 
   
   
     7. An exhaust gas recirculation system for an internal combustion engine, the internal combustion engine including an intake manifold, an exhaust manifold, and a turbocharger compressor coupled with the intake manifold, said exhaust gas recirculation system comprising: an EGR valve fluidly coupled between said exhaust manifold and said intake manifold, said EGR valve including a valve stem, a shield surrounding said valve stem, a purge air inlet associated with said valve stem, said purge air inlet being in fluid communication with said compressor, and a purge air chamber defined by said shield, said purge air chamber in communication with said purge air inlet. 
   
   
     8. The exhaust gas recirculation system of  claim 7 , wherein said EGR valve includes a purge air port terminating at said purge air inlet. 
   
   
     9. The exhaust gas recirculation system of  claim 7 , wherein said EGR valve includes an open frame defining each of said purge air inlet and said purge air chamber. 
   
   
     10. The exhaust gas recirculation system of  claim 9 , wherein said valve stem has a longitudinal axis, and said purge air inlet and said purge air chamber define a cross flow direction transverse to said longitudinal axis. 
   
   
     11. An EGR valve for use in an exhaust gas recirculation system of an internal combustion engine, said EGR valve comprising:
 a valve body; 
 a valve stem carried by said valve body; 
 a shield surrounding said valve stem; 
 a valve disk attached to said valve stem; 
 a purge air chamber defined by said shield; 
 a purge air inlet in communication with said purge air chamber for receiving combustion air; and 
 an EGR inlet for receiving exhaust gas. 
 
   
   
     12. The EGR valve of  claim 11 , wherein said EGR valve includes a purge air port terminating at said purge air inlet. 
   
   
     13. The EGR valve of  claim 11 , wherein said valve body includes an open frame defining each of said purge air inlet and said purge air chamber. 
   
   
     14. The EGR valve of  claim 13 , wherein said valve stem has a longitudinal axis, and said purge air inlet and said purge air chamber define a cross flow direction transverse to said longitudinal axis.